Field of the Invention
The present invention relates to integrated circuits and more particularly generating a reference signal in integrated circuits.
Description of the Related Art
In general, a bandgap reference circuit provides a voltage reference with improved temperature stability and is less dependent on power supply voltage than other known voltage reference circuits. Bandgap reference circuits typically generate a reference voltage approximately equal to the bandgap voltage of silicon extrapolated to zero degrees Kelvin, i.e., VG0=1.205V. To achieve a target reference voltage, these circuits typically use voltage multiplication, which increases output noise. Typical voltage reference circuits include a current mirror coupled to the power supply and the voltage reference node to provide a current proportional to absolute temperature (i.e., PTAT) to the voltage reference node. These circuits can be made with relatively low cost, but have the disadvantages of having high noise for a particular power consumption and being sensitive to power supply noise, which reduces the accuracy of the voltage reference. Accordingly, improved techniques for generating reference voltages are desired.